WO2004066022A1

WO2004066022A1 - Liquid display device with thin film transistors and method of manufacturing same

Info

Publication number: WO2004066022A1
Application number: PCT/CN2003/000067
Authority: WO
Inventors: Maw Song Chen
Original assignee: Quanta Display Inc.; Quanta Display Japan Inc.
Priority date: 2003-01-24
Filing date: 2003-01-24
Publication date: 2004-08-05
Also published as: AU2003207225A1; AU2003207225A8

Abstract

The present invention relates to a liquid display device with thin film transistors and a method of manufacturing such device, whereby the number of the masks for array fabrication can be decreased. The method comprises the following steps: depositing a first metal layer on a transparent substrate, and defining the first metal layer to form at least two gate electrodes adjacent to each other; forming a gate electrode insulating layer on the surface of the said gate electrodes.; forming a semi-conduct layer on the insulating layer, and defining the same to form a prescribed pattern; depositing a second metal layer on the said transparent substrate, and defining the second metal layer to form a source/drain electrode metal layer; depositing a insulating layer on the said transparent substrate; defining the insulating layer, the source/drain electrode metal layer and the gate electrode insulating layer to form a contact window, and the contact window is located between the two gate electrodes; depositing a transparent conduct layer on the said transparent substrate; and forming a black matrix which covers the corresponding region above the contact window.

Description

Thin film transistor liquid crystal display and manufacturing method thereof

The present invention relates to a thin film transistor liquid crystal display and a manufacturing method thereof, and particularly to a manufacturing method capable of reducing the number of array photomask layers of a thin film transistor liquid crystal display. Background technique

Liquid crystal display (hereinafter referred to as LCD) is one of the most widely used flat-panel displays at present. It has the characteristics of low power consumption, thin and light weight, and low-voltage driving. It can be applied to personal computers, word processors, and navigation. Display systems for systems, recreational instruments, projectors, view finder, and portable devices in daily life, such as watches, computers, televisions, etc.

The display principle of the liquid crystal display is to use the dielectric anisotropy and conductive anisotropy of the liquid crystal molecules. When an electric field is applied, the arrangement state of the liquid crystal molecules is switched, which causes various photoelectric effects of the liquid crystal film. Thin film transistor (hereinafter referred to as TFT) -LCD uses TFT as the active element, which has the advantages of low power consumption, low voltage driving, thinness and lightness.

Please refer to FIGS. 1A to 1E. FIGS. 1A to 1E are cross-sectional views showing a manufacturing process of a conventional thin film transistor liquid crystal display. First, as shown in FIG. 1A, a metal layer, such as molybdenum / aluminum-neodymium alloy, is deposited on a transparent substrate 21, and then a photo-etching process (lithographic etching process) is used to define the metal layer to form a gate electrode. (Gate electrode) 22. Next, a gate insulating layer 23 is formed on the surface of the gate electrode 22.

Then, as shown in FIG. 1B, an insulating layer 24, a first semiconductor layer 25, such as an amorphous silicon (hereinafter referred to as a-Si) layer, and a second semiconductor layer 26 are sequentially deposited on the transparent substrate 21. , Such as a miscellaneous silicon layer (n + doped amorphous silicon). After that, the insulating layer 24, the first semiconductor layer 25, and the second semiconductor layer 26 are defined to form a layer as shown in the figure. Shown island structure.

Next, as shown in FIG. 1C, an aluminum alloy layer is deposited on the transparent substrate 21, such as pure aluminum metal, aluminum-niobium alloy, aluminum-neodymium alloy, aluminum-titanium alloy, or aluminum-silicon-copper alloy. Then, a photo-etching process is used to define the metal layer to form a signal line 27 and a source / drain metal layer. The source / drain metal layer includes a source electrode 31 and a drain electrode 32 spaced a channel 28. And expose the first semiconductor layer 25 in the channel 28.

Then, as shown in FIG. 1D, a protective layer 34 is deposited on the transparent substrate 21 to completely cover the entire TFT element, but the contact window 30 is exposed to protect the element from external interference. The protective layer 34 is, for example, a silicon nitride layer.

Finally, an indium tin oxide (ITO) layer is deposited on the transparent substrate 21 and a photo-etching process is performed to define the indium tin oxide layer as a signal line region 36 and a pixel region 38, such as Figure 1E.

FIG. 2 is a cross-sectional view showing another conventional thin film transistor liquid crystal display. The cross-sectional view mainly shows a capacitor storage portion of the thin film transistor liquid crystal display. The manufacturing process of such a conventional thin film transistor liquid crystal display requires six photo-etching processes. First, a first metal layer is deposited on a transparent substrate 50, and then the first photo-etching process is used to define the first metal layer to form a gate. Electrode 52. After that, a gate insulating layer 54 is formed on the surface of the gate electrode 52, and the second insulating layer is used to define the gate insulating layer 54. A semiconductor layer (not shown) is formed on the gate insulating layer 54, and the semiconductor layer is defined by a third photo-etching process. Next, a second metal layer is deposited on the transparent substrate 50, and then a fourth photo-etching process is used to define the second metal layer to form a source / drain metal layer 56. Second, a protective layer 58 and a flat layer 60 are sequentially deposited on the transparent substrate 50 to completely cover the entire TFT element to protect the element from external interference. Then, a fifth photo-etching process is performed to define The flat layer 60 and the protective layer 58 form a contact window. Finally, an indium tin oxide layer 64 is deposited on the transparent substrate 50 and a sixth photo-etching process is performed to define the indium tin oxide layer 64 as A signal line area and a pixel area.

After the above process, a process of forming a color filter 70, forming a spacer, and a liquid crystal 72 is further included.

Because the traditional TFT requires two contact window manufacturing processes, the existing TFT manufacturing process requires as many as six masks and multiple photolithography processes, which will cause problems such as low yield and high cost. . Summary of the Invention

In view of this, the present invention proposes a thin film transistor liquid crystal display and a manufacturing method thereof. The manufacturing method can reduce the number of photomasks made by an array, which includes the following steps: depositing a first metal layer on a transparent substrate, and defining Forming a first metal layer to form at least two adjacent gate electrodes; forming a gate insulating layer on the surface of the gate electrode; forming a semiconductor layer on the gate insulating layer, and defining the semiconductor layer to form a predetermined shape; Depositing a second metal layer on the transparent substrate, and defining the second metal layer to form a source / drain metal layer; depositing an insulating layer on the transparent substrate; defining the insulating layer, the source / drain metal Layer and a gate insulating layer to form a contact window; depositing a transparent conductive layer on the transparent substrate, and defining a pixel region and a signal line region; and forming a black matrix region on the corresponding region above the contact window.

The thin film transistor liquid crystal display provided by the present invention includes: a transparent substrate on which at least two adjacent gate electrodes are formed; a gate insulating layer formed on the surface of the gate electrode; a semiconductor defined in a predetermined shape A layer formed on the gate insulating layer; a source / drain metal layer formed on a predetermined region on the transparent base plate; an insulating layer formed on the source / drain metal layer; a contact window, It passes through the insulating layer, the source / drain metal layer and the gate insulating layer and exposes the surface of the transparent substrate between the adjacent gate electrodes; a transparent conductive layer is formed on the transparent substrate; and a black The matrix area is formed in a corresponding area above the contact window.

The method of the present invention can reduce the number of mask formations of the photo-etching process, and therefore can reduce manufacturing time and equipment required for the manufacturing process, increase production and reduce costs; Assist the design of the gate structure. Forming the gate on both sides of the contact window can prevent the contact window from being over-etched and causing a short circuit with the gate. In addition, the black matrix area is formed correspondingly above the contact window to avoid the periphery of the contact window. Light leakage occurs in the area.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to make the foregoing objects, features, and advantages of the present invention more comprehensible, the following describes in detail the preferred embodiments with reference to the accompanying drawings as follows:

1A to 1E are cross-sectional views showing a manufacturing process of a conventional thin film transistor liquid crystal display. FIG. 2 is a sectional view showing the structure of a capacitor portion of another conventional thin film transistor liquid crystal display.

3 is a top view of a pixel layout showing a manufacturing process of a thin film transistor liquid crystal display according to an embodiment of the present invention.

4A to 4E are cross-sectional views showing a manufacturing process according to the AA ′ section of FIG. 3. detailed description

First, referring to FIG. 3, a top view of a pixel layout of a thin film transistor liquid crystal display structure according to an embodiment of the present invention is shown. The thin film transistor liquid crystal display structure includes a transparent substrate 100; a gate region 310; a doped silicon layer 320; a source / drain region 330; a contact region 340; an indium tin oxide layer 350; a black matrix on a color filter Region 360; capacitor line 370 and gate line 380.

4A to 4E show cross-sectional views of the manufacturing process according to the kk! Section of FIG. 3, and these process cross-sections mainly show the capacitor portion of the thin film transistor liquid crystal display. First, as shown in FIG. 4A, a first metal layer, such as a molybdenum-aluminum-neodymium alloy layer, is deposited on a transparent substrate 100, and then the first metal layer is defined by a first photo-etching process to form a gate.极 electrode (gate electrode) 102.

Next, as shown in FIG. 4B, a gate insulating layer 104 is formed on the surface of the gate electrode 102. For example, a chemical vapor deposition process is used to deposit an oxide layer. After that, a semiconductor layer (not shown), such as an n + doped amorphous silicon layer, is formed on the gate insulating layer 104. After that, the second photo-etching process is used to define the semiconductor layer.

Then, as shown in FIG. 4C, a second metal layer is deposited on the transparent substrate 100, such as pure aluminum metal, aluminum-niobium alloy, aluminum-neodymium alloy, aluminum-titanium alloy, or aluminum-silicon-copper alloy. Then, a third photo-etching process is used to define the second metal layer to form a source / drain metal layer 106.

Secondly, as shown in FIG. 4D, an insulating layer is sequentially deposited on the transparent substrate 100, such as a protective layer 108 having a protective function and a flat layer 110 for planarization, so as to completely cover the entire TFT element, so that Protects components from external aggressions. The protective layer 108 is, for example, an oxide layer or a nitride layer formed by a chemical vapor deposition method, and the flat layer 110 is, for example, an oxide layer formed by a chemical vapor deposition method. Then, a fourth photo-etching process is performed to define the flat layer 110, the protective layer 108, the source / drain metal layer 106, and the gate insulating layer 104 to form a contact window 112, and the contact window 112 is located on the gate Between the electrodes 102, and the gate electrode 102 and the contact window 112 are not connected.

Finally, as shown in FIG. 4E, a transparent conductive layer, such as an indium tin oxide layer 114, is deposited on the transparent substrate 100, and a fifth photo-etching process is performed to define the indium tin oxide layer 114 as a signal line area and a pixel. (Pixel) area.

Referring to FIG. 4E again, an embodiment of the present invention further includes forming a color filter 120 at a specific distance from the transparent substrate 100. Thereafter, a black matrix region 122 is formed on a corresponding region of the color filter 120 corresponding to the contact window 112. The purpose of forming the black matrix region 122 is to shield the edge domain from light leakage. Then, a spacer and a liquid crystal 124 are formed between the transparent substrate 100 and the color filter 120.

As mentioned above, the thin film transistor liquid crystal display of the embodiment of the present invention includes a transparent substrate 100, on which at least two adjacent gate electrodes 102 are formed; a gate insulating layer 104 is formed on the surface of the gate electrode 102; a semiconductor layer (not shown) defined in a predetermined shape is formed on the gate insulating layer 104 A source / drain metal layer 106 is formed on a predetermined area on the transparent substrate 100; a protective layer 108 and a flat layer 110 are formed on the source / drain metal layer 106; a contact window 112 passes through the protective layer 108; , A flat layer 110, a source / drain metal layer 106 and a gate insulating layer 104 and expose the surface of the transparent substrate 100; an indium tin oxide layer 114 is formed on the transparent substrate 100; and a black matrix region 122 is formed on the contact window The corresponding area above 112.

In the process of etching the protective layer to form a contact window, the present invention continues to etch the contact window to the source / drain metal layer and the gate electrode, so that the photo-etching process / process defining the gate insulating layer can be omitted . In the capacitor region, the gate is also dug out to avoid a short circuit between the source / drain metal layer and the indium tin oxide layer. The method of the present invention reduces the number of masks in the photo-etching process, so it can reduce manufacturing time and equipment required in the manufacturing process, increase yield and reduce costs; and meanwhile, the gate is formed on the gate structure through the design of the gate structure. On both sides of the contact window, the contact window can be prevented from being over-etched and short-circuited with the gate; in addition, because a black matrix region is correspondingly formed above the contact window, light leakage can be avoided in the peripheral region of the contact window.

Although the present invention has been described above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various improvements or changes without departing from the spirit and scope of the present invention. Changes, these should all belong to the protection scope of the present invention. Reference Signs

100 ~ transparent substrate; 310 ~ gate area; 320 ~ doped silicon layer; 330 ~ source / drain area; 340 ~ contact area; 350 ~ indium tin oxide layer; 360 ~ black matrix area; 370 ~ capacitor line 380 ~ gate line 102 ~ gate electrode 104 ~ gate insulating layer 106 ~ source / drain metal layer 108 ~ protective layer 110 ~ flat layer 112 ~ contact window 114 ~ indium tin oxide Layer; 120 ~ color filter; 122 ~ black matrix area; 124 ~ spacer and liquid crystal.

Claims

Rights request

1. A method for manufacturing a thin film transistor liquid crystal display, comprising the following steps:

Depositing a first metal layer on a transparent substrate, and defining the first metal layer to form at least two adjacent gate electrodes;

Forming a gate insulating layer on the surface of the gate electrode;

Forming a semiconductor layer on the gate insulating layer, and defining the semiconductor layer to form a predetermined shape;

Depositing a second metal layer on the transparent substrate, and defining the second metal layer to form a source / drain metal layer;

Depositing an insulating layer on the transparent substrate;

Defining the insulating layer, the source / drain metal layer and the gate insulating layer to form a contact window, and the contact window is located between the adjacent gate electrodes;

Depositing a transparent conductive layer on the transparent substrate; and

A black matrix area is formed on the corresponding area above the contact window.

2. The method for manufacturing a thin film transistor liquid crystal display according to claim 1, wherein the first metal layer is a molybdenum / aluminum-neodymium alloy layer.

3. The method for manufacturing a thin film transistor liquid crystal display according to claim 1, wherein the second metal layer is pure aluminum metal, aluminum-niobium alloy, aluminum-neodymium alloy, aluminum-titanium alloy, or aluminum-silicon- Copper alloy.

4. The method for manufacturing a thin film transistor liquid crystal display according to claim 1, wherein the gate insulating layer is formed by depositing an oxide layer using a chemical vapor deposition process.

5. The method for manufacturing a thin film transistor liquid crystal display according to claim 1, wherein The insulating layer is formed by depositing an oxide layer or a nitride layer by a chemical vapor deposition process.

6. The method for manufacturing a thin film transistor liquid crystal display according to claim 1, further comprising:

Forming a color filter at a specific distance from the transparent substrate; and forming a black matrix region on a corresponding region of the pair of corresponding color contacts on the color filter.

7. The method for manufacturing a thin film transistor liquid crystal display according to claim 1, wherein the gate electrode is not connected to the contact window.

8. A thin film transistor liquid crystal display, comprising: a transparent substrate on which at least two adjacent gate electrodes are formed;

A gate insulating layer formed on the surfaces of the gate electrodes;

A semiconductor layer defined in a predetermined shape is formed on the gate insulating layer; a source / drain metal layer is formed in a predetermined region on the transparent substrate;

An insulating layer formed on the source / drain metal layer;

A contact window that passes through the insulating layer, the source / drain metal layer and the gate insulating layer and exposes the surface of the transparent substrate between the adjacent gate electrodes;

A transparent conductive layer formed on the transparent substrate; and

A black matrix area is formed in a corresponding area above the contact window.

9. The thin film transistor liquid crystal display according to claim 8, wherein the gate electrode is a molybdenum / aluminum-neodymium alloy.

10. The thin film transistor liquid crystal display according to claim 8, wherein the source / drain metal layer is pure aluminum metal, aluminum-niobium alloy, aluminum-neodymium alloy, aluminum-titanium alloy, or aluminum-silicon- Copper alloy.